Why are there different styling in Meta from AskUbuntu?

Question

I have noticed this a while, but it is just a bit weird.

Styling differences occur between different StackExchange sites. The most notable is the <kbd> tag, most of which render the contents of posts like what is on AskUbuntu.

On AskUbuntu, <kbd>Alt</kbd>+<kbd>Tab</kbd> looks like:

Where as here on Meta, it is fairly bad:

This does not seem to happen on Unix & Linux Meta, or Raspberry Pi Meta, or SO Meta.... (previews - the thing it shows beneath when typing a question)

I am not sure whether it has always been like this here on Meta, but I do know they use to look like this. So why does Meta currently have that clunky old style?

Looking at what is rendered in my Firefox (27) browser, Meta and AskUbuntu are using different style sheets, which is understandable as it is dull grey here instead of Ubuntu orange.

Oh, and if someone does bother to change it in future, here is it in markdown/html:

Alt+Tab

_{Other issues may have happened due to this.}

Answer 1

I completely forgot about this... - this other post now has a answer by Oli (and has been marked as a dupe of this one):

I won't say this is by design, but this is not a bug. It's just how the style is currently on Meta. Firefox is square and blocky too.

The main site is fine (even in Chrome). Here's an example post.